John Charles was integral to the Olmsted firm, further developing many of the park and city-planning projects begun by his father, Frederick Law Olmsted, Sr. These included work in Buffalo, Brooklyn, Milwaukee and Louisville, as well as in Boston's "Emerald Necklace" where he played a key role.His first major solo park project was Audubon Park in New Orleans where he incorporated the ideas Olmsted Sr. had used at the World's Columbian Exposition and at Boston's Back Bay Fens to transform swampy ground into a scenic park.John Charlesexpanded the firm's practice to new projects across the continent, including park systems, estates and subdivisions in New Jersey;Dayton, Ohio;and in the Pacific Northwest and British Columbia.Many of these projects significantly influenced the manner in which cities developed. Within the Olmsted firm, he created efficient design and business procedures necessary to manage a growing design office with a widespread practice and to help train the next generation of landscape architects, many of whom would eventually form independent practices.John Charles' work nurtured the nascent profession of landscape architecture, and he became the first president of the American Society of Landscape Architecture when it was formed in 1899.